In process, as well as manufacturing, automation technology, field devices are often applied for registering and/or influencing process variables. Serving for registering process variables are measuring devices, such as, for example, fill-level measuring devices, flow measuring devices, pressure- and temperature-measuring devices, pH-measuring devices, conductivity measuring devices, etc., which register corresponding process variables, fill-level, flow, pressure, temperature, pH-value and conductivity, respectively. Serving for influencing process variables are actuators, such as, for example, valves or pumps, via which e.g. flow of a liquid in a pipeline or fill-level of a medium in a container is changed. Field devices include, in principle, all devices, which are applied near to the process and which deliver, or process, process-relevant information. A large number of such field devices are available from the members of the firm, Endress+Hauser.
In modern industrial plants, field devices are, as a rule, connected via bus systems with at least one superordinated unit. Examples of suitable bus systems include the Profibus®, Foundation Fieldbus® and HART® bus systems. Normally, the superordinated unit is a control system or a control unit, such as, for example, a programmable logic controller, i.e. a PLC. The superordinated unit serves for process control, process visualization, and process monitoring, as well as for start-up and servicing of the field devices. Programs, which run independently on superordinated units, include, for example, the operating, or servicing, tools, FieldCare of Endress+Hauser, Pactware, AMS of Fisher-Rosemount, and PDM of Siemens. Operating, or servicing, tools integrated in control-system applications include PCS7 of Siemens, Symphony of ABB and Delta V of Emerson.
Integration of field devices into object-based configuration, or management, systems is accomplished via device descriptions, which enable the superordinated units to recognize and interpret data delivered from the field devices. Device manufacturers provide the device descriptions for each of their field device types, or for each of their field device types in different applications. In order that the field devices can be integrated into different fieldbus systems, furthermore, attention must be paid to the fact that different device descriptions need to be created for the different field bus systems. Thus, there are e.g. HART-, Fieldbus Foundation- and Profibus-device-descriptions.
In order to create a universal description for field devices, Fieldbus Foundation (FF), HART Communication Foundation (HCF) and Profibus Nutzerorganization (User Organization) (acronym PNO) have defined a universal electronic device description (Electronic Device Description EDD); this is defined in the standard IEC 61804-2.
For comprehensive servicing of field devices, recently, special device descriptions, so-called DTMs (Device Type Managers, or device managers) have become available. These meet the FDT (Field Device Tool) specifications. The FDT specification, serving as an industrial standard, was developed by PNO, in cooperation with ZVEI (Zentralverband Elektrotechnik—und Elektroindustrie, or, in English, German Electrical and Electronics Manufacturers' Association). The up-to-date FDT specification can be obtained from ZVEI, PNO, or the FDT Group.
Many field device manufacturers deliver, along with their field devices, the relevant DTMs. The DTMs include all device-specific data, functions and operational rules, such as e.g. device structure, existing communication options, and a graphical user interface, or GUI, for the particular field device, or for a particular family of field devices.
As run-time environment, DTMs require a frame application, this being, here, the FDT frame. The frame application and the relevant DTMs allow for very comfortable accessing of field devices, e.g. access to device parameters, measured values, diagnostic information, status information, etc., as well as enabling invoking of special functions made available by the particular DTMs. Frame application and DTMs form, together, an object-, or component-, based, management, or configuration, system for field devices. In order that the DTMs of different manufacturers can function correctly in the frame application, the interfaces to the frame application and to the various DTMs must be clearly defined. This matter of interfaces is an FDT concern. The FDT technology unifies the communication interface between field devices and superordinated unit. A special attraction of this technology is that it functions independently of applied communication protocol, software environment, field device, and superordinated unit. FDT technology makes it possible to create a functioning whole out of any combination of field devices, superordinated systems, and protocols. A known FDT frame application is, as already mentioned, FieldCare, a product of the firm, Endress+Hauser.
If a manufacturer has a large number of field device types, particularly field device types for various applications, in its product portfolio, then the DTMs can accumulate to form a significant DTM-library. Usually, these DTM-libraries are so extensive, that the contained data must be stored on a plurality of CDs. With this are associated some essential disadvantages:    1. In order, in the case of a new issue of the library, to load the DTMs onto an FDT frame application, usually installation times up to several hours are required.    2. In order, then, to integrate the new edition of the DTM-library into an FDT frame application, likewise time-consuming installation procedures are necessary, since, first, the already existing DTMs must be deleted and replaced by the improved, new version. If the new installation does not work, then the original version must be re-installed, with much time consumed.    3. Developers of DTM-libraries must, preliminary to an installation, usually perform a plurality of tests with intermediate versions of the DTMs. Also, here, the time-consuming installations are disadvantageous.    4. Usually, in the case of every installation of the DTM-library, changes are performed on the operating system, on which the frame application and the DTM library are stored. These changes remain, even after deinstallation.    5. A fast configuration of the field devices is not possible, since, always, first the DTM-library must be installed. This is especially disadvantageous, when a user would like to implement only one new field device in its plant and must perform the required parametering for the correct operation of the field device. The time for loading the updated DTM-library exceeds, by a number of times, the time for parametering the field device.